Estimating costs of multiple chronic conditions among adults with diabetes.

Most adults with diabetes have at least one co-existing chronic condition and 40% have three or more. As the number of comorbidities increases, the risks of poor patient outcomes (e.g., unnecessary hospitalizations, adverse drug events, mortality) also increase. Although previous studies have shown that the type and severity of certain conditions, not just the number of comorbidities, matter, less attention has been paid to multiple chronic comorbidities (MCCs) and how MCCs impact diabetes care. Patients with MCCs are known to require high levels of health care and account for a significant proportion of health care costs. However, the most expensive MCC clusters in diabetes have yet to be identified. Nor is it clear how the patterns vary by age. Our recent analysis of 161,174 adult patients with Type 2 diabetes found that the leading MCC combination was the presence of hypertension-hyperlipidemia-obesity and no other diagnosed comorbidities (19% of the sample), based on data from electronic health records, encounter files, and lab values supplied by U.S. providers in the 2008-2012 Humedica datasets. The top 10 mutually exclusive MCC clusters accounted for roughly 70% of diabetes patients. We also found that MCC cluster patterns exhibit substantial heterogeneity across patients and by age. For example, the most notable difference by age was a higher prevalence of obesity in the younger cohort. Unlike previous research that focused on two-way or three-way combinations between and among comorbidities, our analysis examined a large number of the most common MCC combinations for diabetes.